Art of bookbinding



0. LUTOLF. ART OF BOOKBINDINQ." APPLICATION FILED JAN. z]. I920.

Patented Apr. 12, 1921.

UNITED STATES PATENT OFFICE.

o'r'ro Ln'roLr, or sr. GALLEN, SWITZERLAND, ASSIGNOR T0 JOHANNAmicrons-BILL, or s'r. GALLEN, SWITZERLAND.

ART OF BOOKBINDING.

Specification of Letters Patent. i Patented A 12 1921 Application filedJanuary 27, 1920. Serial No. 354,395.

To all to 7mm it may concern:

Be it known that I, Or'ro Lii'roLF, a citizen of the SwissConfederation, and residing at St. Gallen, Switzerland, have inventedcertain new and useful Improvements in the Art of Bookbinding, of whichthe following is a specification.

The present invention has reference to certain new and usefulimprovements in the bookbinding art, and it relates more particularly toan improved method of attaching the gathered sheets or signatures of abook by means of wire staples to the cross-tapes which are to be aflixedto the cover flaps in well known manner, and the object of the inventionis to improve on the wirestitching as now conventionally practised by soinserting, bending and driving-in the wire staples that their free shankends are countersunk or anchored, as it were, into the cross-tape andthe fold of thesheets, for the purpose of affording the staples a firmpurchase on the tape which prevents relative displacement, and forpreventing the staples from opening up again, the shank points in thislatter instance readily giving rise to injuries to the smoothing handofv the operator.

My invention will best be understood when described in connection withthe accompanying drawing, in which Figure 1 represents a perspectiveview of a plurality of signatures wirestitched by my improved method toa cross-tape; Figs. 25 show sections through a number of folded sheetswith the wire staple in. its successive operative stages; Figs. 6l0 showsimilar views when using asomewhat longer staple.

Referring first to Figs. 1-5, the reference numeral 2 denotes the wirestaples, 3

the gathered sheets or signatures, and 5 the back tape. Each staple 2,which comprises the bridge portion and the two rectangularly extendingshanks 1, is driven by special machinery through the fold of the sheets3 from within the latter outwardly so that the shanks 1. protrudethrough the fold edge (Fig. 2); next the extreme free ends of the shanksare bent inwardly to form short prongs 4 (Fig. the cross-tape 5 is theninserted between the shanks, the latter are folded over down onto thefold of the sheets (Fig. l) and are finally forced down flat inparallelism with the staple bridge, the lnbent prongs & entering theclenched tape 5 (Fig. 5). The staple ends thus are securely anchored inthe tape, preventing relative lateral displacement of the parts and theyare not liable to spread again to interfere with the ensuingmanipulations.

In order to clenchingly secure the staples to sheets and tape theirshanks may be made somewhat longer (Fig. 6) and their extremities l arebent off to a reater extent and at a slightly acute angle *ig. 7) thecrosstape 5 is inserted (Fig. 8), the staple ends 4: are driven homethrough tape 5 and sheets 3 (Fig. 9) and they are finally rolledinwardly and clenched (Fig. 10) by contacting with, and sliding awayfrom each other on, the staple bridge.

All these operations are carried out mechanically by a special machinewhich forms phe subject matter of a separate applicaion.

What I claim is 1. The herein described method of wirest1tching sheetsor signatures to cross-tapes, which consists in driving the staple,which comprises a bridge portion and two rectangularly extending shanks,through the fold of the sheets or signatures from within outwardly,inbending the free extremities of the shanks, insertlng the cross-tapebetween the shanks, and bending inwardly the shanks down flat onto thecross-tape, forcing therelpy said inbent shank extremities into the ape.

2. The herein described method of wire- .stitching sheets or signaturesto the crosstapes, which consists in driving the staple, which comprisesa bridge portion and two rectangularly extending shanks, through thefold of the sheets or signatures from within outwardly, sharplyinbending the free extremities of the staple shanks at a slightly acuteangle and their inbent portion being longer than the combined thicknessof cross tape and sheets, inserting the cross-tape between the shanks,bending down the shanks onto the tape, forcing thereby the said inbentshank extremities through the tape and underlying sheets and causingthem to be clenchingly deflected by the staple bridge.

OTTO LllTOLF.

